There is no four-level requirement for the re-examination of the Food College of Northeast Agricultural University. According to relevant information, the postgraduate entrance examination does not stipulate that candidates must hold a CET-4 certificate. As long as the candidates' academic qualifications meet the requirements, they can apply for the exam. Postgraduate re-examination is an important part of the postgraduate examination system, that is, the second examination organized by the applicant institutions after passing the initial examination of postgraduate entrance examination.